Air-lift apparatus



E. M. ROGERS.

AIR LIFT APPARATUS. APPLICATION FILED APR. 5. 1920.

Patentqd Apr. 19, 1921.

ars, M-

EDWIN M. ROGERS, OF NEW YORK, Y.

AIR-LIFT ArPmArUs.

Specification of Letters Patent. Patented Apr. 19, 1921.

Application filed April 5, 1920. Serial No. 371,392.

To all whom it may concern:

Be it known that I, EDWIN M. Rooms, a

citizen of the United States, residing in New York, in the county of NewYork and State of New York, have invented certain new and usefulImprovements in Air-Lift Apparatus, of which the following is aspecification.

This invention relates toliquid-elevating apparatus of the classcommonly known as air-lifts, and aprincipal object is to furnish for usein .such apparatus, an improved means or regenerator, whereby toregenerate a liquid column consisting of mixed liquid and large orcoalesced air-bubbles, into a column of mixed liquid and small bubbles,

and thereby reduce the slippage of the air-bubbles upwardly in thecolumn, and reduce the loss otherwise normally incident to thatwell-known action. A further object is to provide a regeneratorof thatclass adapted to effect said'object in a continuous-moving column, sothat the column need notbe subjected to a cessation of upward flow atany point in the height thereof, and thus to reduce or avoid the loss ofcis mica otherwise normally occurring from such causes. Further objectsand advantages are pointed out and explained in the course of thefollowing description.

. The present invention is thus, in part, in

the nature of an improvement on the air-lift a paratus which isdescribed and claimed in U nited States Patent No. 1,339,137 granted tome May 4, 1920, on my copending application Serial No. ,.320,652, filedAugust 29, 1919. I I

In the drawing accompanying and forming'a part of this specification,Figure 1 is a side elevation of an air-lift apparatus and systemarranged in accordance with my present invention; this view illustratesthe general arrangement, including the use of a plurality of'theregenerators, as G G and a system of upwardly progressing gradation asregards the regenerators, the conduit members of an uptake pair, and ofsuccessive uptake pairs, as hereinafter more fully explained.

Fig. 2 is a vertical, central section,-on line 2, 2, Fig. 3,-through,one of said regener-ators, and is drawn partially in a diagrammaticmanner for more clearly indicat- 1n the mode of action of thisapparatus.

1 3 is a cross-sectional view inline 3,v 3, of 1g. 2, for showing apreferred way of constructing and arranging the casing and the inclosedair-collecting chamber of the regenerator.

Fig. 4 is a view similar to Fig. 2, for illustrating a modification asregards certain features of the invention, as hereinafter more fullyexplained.

Fig. 5 is a cross-sectional view in .line 55, ofFig. 4.

Fig. 6 is a side elevation of a modified form of the regenerator, andthe lower portion is here shown broken away to exhibit an additionalimprovement which is applied in such a manner as to accelerate the Segregation of the air in the de-aerating zone.

' Figs. 7, 8 and 9 are cross-sectional views in lines 77, 8-8, and 9-9,respectively, of Fig. 6, for more fully illustrating a preferred form orarrangement of the improvements specially shown in Fig. 6.

Similar charactersdesignate like partsin all the views.

In the form of apparatus shown in Fig. 1, the total submergence effectshould correspond, substantially as in ordinary practice,

to the total height to which the fluid is to be elevated and thequantity'of air to be used for aerating the uptake columnitosufliciently reduce the weight thereof as compared with the weight, orgravity effect, of the submergence column. In some instances, ifdesired, the total submergence effect may be obtained, by a relativelyshort height of the submergence column combined with a mechanicallyoperated fluid-impelling. means; this arrangement is not hereinillustrated, but one form thereof is described in. my prior Letters-Patent No. 1,319,797 dated October 28th, 1919, to which reference may behad.

In considering the operation of the present apparatus, it will beconvenient to regard the up-flowing column as being composed of twostreams, one composed of liquid and the other of air, these streamsbeing each incorporated in, 'or with the other, and the air relativelyto) the liquid stream. This compound stream on arriving, or as itarrives, at the entrance of a regenerator, is there segregated so thateach of said parts (or individual streams) thereof is concentrated, .andthe two streams thus formed are diverted each from the other, intoseparate channels, respectively. This separation and'diversion is hereinshown accomplished by a- ,method according to which the liquid stream isslackened in velocity simultaneously,-or nearly so,with the discharge ofthe aircontents into an air-collecting chamber, which chamber also formsa conduit member for the air stream. The diverted liquid stream passesupward through a separate conduit member, or channel, and is rechargedwith the air-stream in an upper zone of the regenerator. Thus said twostreams after being for a brief time segregated or dis-incorporated, arefinally re incorporated into a compound stream which then enters anuptake conduit at the upper end of the regenerator. And, during thesesuccessive operations or stages, each said: stream flows oncontinuously, but has for a short distance, a modified velocity.

In the arrangement of the air-lift apparatus, as herein shown in Fig. 1for the purposes of illustration, the uptake line or column comprises alower air-lift pipe or uptakeconduit, as P, a second such pipe orconduit, as P, and the upper and similar pipe or conduit P The lowerpair of pipes P P are connected by a regenerator G and the next pair ofpipes P P are similarly connected by a regenerator, G Said uptake linemay be supported in practice in any convenient manner, as for instance,by some suitable stand or base as D; this is shown in Fig. 1, arrangedfor directly supporting the pipe P. Instead of this support, the entireuptake line may be suspended in some instances, if desired, by means ofapparatus such as commonly employed for analogous purposes in miningoperations, but such devices being wellknown, are not hereinillustrated.

Said uptake line, comprising a plurality of pipes, P, and a plurality ofconnecting regenerators, G, is shownin Fig. 1, set in a deep well Wcorresponding, for instance, to a mine shaft. The pipe 21, havingthere-, in a regulating valve, or stop valve 21, is shown leading downsaid shaft to the lower end of the uptake line for the purpose ofconveying compressed air from a suitable source thereof (not hereinshown) to an aerating nozzle at N. This nozzle may be of any ordinary orwell known description, such, for instance, as commonly used in the owerend of air-lift pipes, and hence this device is not herein particularlyillustrated or described. However, in practice I prefer to employ assuch initial aerating means, an

ordinary perforated air-lift nozzle, this being preferably arrangedwithin a surrounding hood in a well known manner, whereby to finelysub-divide or comminute the air into small masses or bubbles.

The shading at line 24, (Fig. 1), indicates a water level, and thedistance from said line to nozzle N being the submergence head. To makethe system operative, of course, the contents of the uptake line must belightened by the aeration as to be overbalanced by the submergenceeffect at the level N; this, however, is a principle now wellunderstood.

The detailed construction of a preferred form of the air-bubblesregenerator, G, is best indicated in Figs. 2 and 8. The casing or body,B, is tubular in form, and much larger than conduit P P and ispreferably substantially cylindrical in section, (Fig. This casing, B,is also preferably divided longitudinally into two parts, (preferablybut not necessarily alike), these parts being releasably united bysuitable means,-as, for instance, flanges and bolts indicated in Fig. 3.The mid-length part, or zone, Z (Fig. 2) is shown cylindrical, and ashaving at each end thereof converging zones, Z Z, formed in a nearlyconical manner, and provided with means, as flanges f, f for releasablyattaching the casing B to the conduits P and P respectively.

Within said casing B," and centrally-disposed therein, the combinedair-collecting chamber and air-stream conduit-member, M, 100 issupported within said zone Z and below the converging end Z of thecasing, and has appurtenant thereto an air-comminuting means, at F,adjacent to said converging zone Z thus the space S, between said zone105 Z and comminutor F, constitutes a re-aeration zone, when this termis applied to an interior space. 1

Said chamber M is also shown in axial alinement with the casing B, andwith the 110 coactive conduit-members P P so that the comminutingdevice, F, is concentric with such axes, and also with the casingzone.Z*, which is upwardly converging when the regenerator, G, is inposition for operation; 116

also, the chamber M is shown extending from said lower, or de-aerationzone, Z to said upper, or re-aeration zone, Z and the air-comminutingmeans with which this chamber is provided, is located below said 120upper zone.

hen the regenerator is of the general form indicated in Figs. 2 and 3 itmay be constructed, in practice, in various ways. For instance, theair-chamber M having been constructed and provided with wings n, n,(Fig. 3), this member may be embedded within a core and the casing Bthen cast in one piece, in accordance with methods well-known tofoundrymen. However,

for general use, it is deemed to be preferable to make said casing, orshell in halves, as shown in Fi 3, each of these parts 6 6 .beingprovide with'pairs of flanges, 6, 6

and 7, 7 respectively, by means of which these half-parts may bereleasably secured together b means of ordinary bolts, (not shown). 11this case,- the wings. n n .may

be shaped to fit into recessesforme at t, t,

flanges as g, g, and these pairs of flanges (not shown),

may be held together by bolts, in a usual and obvious manner. But insome instances, if desired, especially when the pipes'are of small size,ordinary screwed pipe-joints maybe used in place of the flanges, as willbe evident to practical mechanics, without a more particulardescription. 1

One object attained by the arrangemen shown in Figs. 1 and 2, is tospread the upflowing column of liquid as this emerges from the lowerconduit P so that the stream of mixed air and liquid extends aroundalarger circle, or zone, and thus reduces in velocity of upward flow inthe separation space within zone Z for thereby accelerating andfacilitatin the completeness of such separation; this eing accomplished,the liquid thus de-aerated is guided toward and into the chamber'leadingto the upper conduit; this action is indicated,approximately, by arrowsand representations of enlarged bubbles in said zone,'Z Fig. 2.

A further advantage of said arrangement of Figs. 1 and 2,is that thelower pipe or conduit P and the upper pipe or conduit P are inalinement, so that the-apparatus is readily lowered into and lifted outof a mine-shaft, or other deep and narrow passage within which theair-lift shall be used; this is especially important when, as sometimeshappensin practice, the air-lift is intended for use in a drilled wellor bore. For

instance, in a'ten-in'ch hole bored down into a mine gallery or drift, acomplete and opperable air lift of this kind can now be slid down whenthe pipes, as P P etc.,. are not over five or six inches in outsidediam- Also, the symmetrical arrangement of the chamber wall relative tosaid uptake pipes, produces an exceptionally strong connection for thosepipes, so that the maximum capacity is obtained with a minimum ofmaterial in and weight of the air-lift system.

In the modification partially illustrated by the sectional side view inFig. 4, the

liquid stream, on emerging above the line 12, is diverted a part towardthe right-hand into channel R, and a part toward the lefthand into asimilar channel R. These two channels, R and R, (indicated by arrows r,0", respectively) constitute in efiect the conduit whereby theliquid-stream is carried from the de-aeration zone Z past and outside ofthe air-stream conduit-member M, (this being also the aforesaidair-collecting chamber), which is continuous or closely adjacent to thelower end g, of the upper uptake pipe or column P. This construction ofthe regenerator, however, while deemed to be broadly within the purviewof the present invention, is not specifically claimed herein, but isintended to constitute in part v the subject matter of aseparateapplication to be concurrently pending herewith.

The hereindescribed improvments which are specifically illustrated inFigs. 6 to 9, inclusive, are not specifically claimed herein, but willconstitute in part the subj ect-matter of a separate application to beconcurrently pending herewith.

The preferred mode of diverting and conducting said liquid stream isherein illustrated 1n Figs. 2 and 3, where the channel S for the liquidstream is annular in cross-section, (Fig. 3), so that the air-conduitmem-' ber M is'surrounded by the casing B, and by said annular space orconduit for the separated liquid stream. By this system of organizingthe regenerator, a minimum of lateral diver ence of the liquid stream isrequired, an since this action takes place in a circular zone, so thatthe liquid moves outwardly in all-directions from a central point, 6.,from the conduit axis, as m, Fig. 3), this construction offers a lowresistance to the liquid stream, besides havingimportant advantages asregardsmanufacture, installation of plant, and maintenance.

As an element of the complete air-lift system, the regenerator may besaid to constitute a re-aeration means, since the primary object andfunction thereof is to restore the separated air to the npflowing columnand thereby re-aerate the liquid thereof with newly-formed bubbles ofsmall size, these bubbles being composed of 'the same air which waspreviously segregated from said column. Thus the processv of segregationas effected in said lower-zone, as Z (Fig. 2) may be regarded not as thechief or most essential step, but as a preparatory step preliminary tothe principal step of re-aeration.

Also, it should be understood that, in practice, a large part of allbubbles both large and small, coming up to said lower zone Z willnormally be forced out by the hydraulic 1pressure and flow up into theairchamber but owing to the considerable distance from one aerationmeans (as G Fig. 1) upwardly to the next one, (as G and the constantcoalescing action in the up-fiowing mixed column, a large portion of theair bubbles will have been coalesced to some extent before reaching saidde-aerating zone; hence, it is considered that a chief anddistinguishing function of-said chamber M is for the collection thereinof coalesced air-bubbles from said lower zone.

One feature of my present improvements relates to an organization, in acontinuous air-lift column, of a plurality of the regenerators'connecting at successive elevations, respectively, a plurality of uptakeconduits having preferably, successively increasing capacities andlengths, counting from the lower conduit upwardly. This system oforganization is illustrated in Fig. 1, where the three uptake pipes, orconduits, P P P are'shown respectively, as having lengths in theproportion of 45, 35 and 20; of these the lower pipe P is shown smallestin diameter, while the second pipe P is larger, and the upper pipe P isthe largest. Also, it will be understood that of the two regenerators, GG the lower one should be fitted for action under a pressurecorresponding to the head above this device, whereas the upper one, Gshould have a different construction or fitting, suitable forregenerating the air bubbles under a much lower pressure; and that acorresponding gradation should be followed when a larger series ofregenerators is employed. These adjustments, in practice, are readilymade, (aided, when necessary, by calculation and trial), by selecting asuitable number and size for the outlet holes, as at F, (Fig. 2), in theto or perforated area of the air-chamber Thus the lower regenerator, Gis fitted (in its make-up) for action upon a given flow of air under ahigh pressure while the upper regenerator, G is similarly fitted foracting during the same period of time upon the same quantity of airunder a lower pressure.

It will now be evident that successive uptake pipes P P P Fig. 1, areshown arranged as a series of pairs of uptake conduits, and this seriesmay be extended, in practice, to include three or more such pairs, asmay be for efliciency and economy, under the conditions which may existin any particular instance. The lower conduit, P and the next followingconduit P constitute one said pair, these two conduits being connectedby and through the laterallyclosed regenerator G Said second conduit Pand the upper conduit P constitute another such uptake pair which aresimilarly connected by the upper regenerator G Thus the number of uptakepairs corresponds to the number of the regenerators which are comprisedin the air-lift system.

For said upper connected pair P P, the lower regenerator G serves as ameans for system) serves as one suitable means for aerating the liquidstream which is supplied through the lower pipe P to the regenerator Gof this lower*pair. Thus, in the complete system, each said uptake paircomprises an intermediate regenerator and a means at the lower end ofthe pair for preliminarily aerating the liquid stream which is toibesupplied to this regenerator.

When the series ofregenerators. are each properly graduated (aselsewhere herein explained) as regards position and working pressure,and are structurally adjusted for comminuting and delivering each thesame air at successively reduced pressures, respectively, theseregenerators are then a plurality arranged in a series having aprogressive. gradation extending from the lowermost regenerator (as G,Fig. 1,) upwardly to the uppermost regenerator of the series. Thisfeature as regards gradation also applies to the conduit-members of anuptake pair, when the upper said member of a given pair has a capacityor a cross-sectional area larger than the lower said member of thesamepair; and, similarly, the successive pairs of uptake conduits mayhave such a progressive gradation as uptake pairs. By means ofthesegradations the acceleration of the upflowing compound column of air andliquid may be lessened or restricted as compared with the accelerationotherwise normally resulting from the continuous expansion of theair-content of the column in passing from the submergence pressure atthe lower end of conduit member P upwardly to the outlet at atmosphericpressure.

In some instances, in an uptake column comprising a plurality of pairsof uptake conduits, only one of these pairs may have the describedgradation arrangement; but this may be in a combination having the twoconduit members of one of said pairs arranged in the upwardlyprogressing gradation; and, in such a limited combination, a series oftwo (or more) of the regenerators may have the described upwardlyprogressing gradation, while each regenerator (in whichever paircomprised) delivers into an proportion to the volume of the water) willdepend on a pressure due tothe toal head to which the air is thensubjected. The proportionate volume, however, of the air content,necessarily continues to increase through the entire height of theair-lift column,.since the air necessarily expands in proportion toreduction of head and pressure,-so that the volumetric ratio of air towater is least in lower pipe P is larger in m 1ddle pipe P and is muchlarger in upper pipe P 1 and, evidently, the weight of a vFig. 1, incombination with the successive regenerators of graded action andeffect, respectively, whereby each regenerator receives' and deliversthe same quantity of air as each other one, but in a volume and of apressure due to, its own position in the height of the air-lift column.

In accordance with the explanation given in my aforesaid priorapplication, it is contemplated, in applying my present invention, tolimit each uptake conduit member, as P P etc.,to such moderate distancesor height as will avoid any considerable loss of power by reason ofincreasing slippage,

' fully explained.

and to discharge the associated air andliquid directly into aregenerator for separa-' tion, and thence (after comminution)'.into

a second or next higher air-lift plpe, as P or P extending upwardly tothe height re quired. But if the total height is deemed too great foreconomy of operation, three or more of the regenerators may be used insome instances, as elsewhere herein more en asingle conduit-member, as Por P extends through a considerable height, the relatively greatexpansion of the aircontent of the upflowing column, makes it desirableto provide for converting such-air into a largely increased number ofbubbles for delivery to the next. following conduitmember; and,hence-,in practice, such next following pipe, (as,P ,ne-xt after P or P, nextafter P asthe case may be), may be made of a proportionately largercross-sec tional 'area,.-as compared with such area of the nextpreceding pipe,in order toavoid an undue increase in the upward velocityof the regenerated air-and-liquid column.

As also. pointedout said prier appliv cation, the expansion of theup-flowing air bubbles results in a constantly increasing slippagevelocity. and pipe-surface friction of the fluid column at successivepoints upwardly from the aerator, and also correspondingly increase thevolumeof a given weight of the aerated fluid, as this approaches thedischarge end of the air-lift pipe. The phenomena, which necessarilyoccur in each of the air-lift pipes, as P and P constitute one reasonwhy it has hitherto been found undesirable, because of waste and loss,to employ air-lifts in many situationsto which otherwise, this systemwould be well adapted. I

It will be remembered that in a mixed column of bubbles and liquid, thecolumn normally moves more rapidly in thecentral portion than it doesnear the conduitwall, and that the larger bubbles naturally tend byreason of their higher slippage velocity, to overta e and thus coalescewith other bubbles, and thereby form by the coalescence, masses, orbodies of air constantly increasing in size and consequently of a stillhigher slippage. velocity. Also, these augmented air bodies tend tofollow a central path withinthe conduit, and thus partake of the mostrapid velocity in the liquid column or stream, in addition to saidincreased slippage. Under these conditions, when the column-velocity isreduced by the upwardly and outwardly tapering part of the conduit,

as shown at Z (Figs. 2, 4 and 6) in the de-aeration zone Z said highvelocity .of the enlarged bubbles quickly carries them upwardly throughsaid zone Z and into the open lower end, at M, of the air-collectingchamber M. Thusthe mode of action is such that the larger and centrallylocated bubbles may be said to be forcibly discharged upwardly out ofthe'liquid column, which is thus de-aerated in passing through said.zone Z this being done simultaneously with the diversion of said liquidinto the by-pass channel,-as R, R, Fig. kl, or S, Fig. 2.

The column being thus freed of its aircontent, or admixture, occupies aproportionally less space as a liquid, and passing into the by-passchannel moves more slowly but without cessation of flow through thischannel; but, on coming into the'contracting portion at Z, in there-aerating zone) of the casing wall, the velocity of the liquid-- isthereby normally increased; and, since this action occurs in connectionwith the incorporation into' the liquid of bubbles of air dischargedthrough the numerous small openings, F,- the column-in a regeneratedform is delivered into the upper conduit P at a proper and relativelyhigh velocity.

The gain directly resulting from a regeneration of a mixed column ofliquid and large bubbles into a column having the bubb g y rt llfitil insize, is understood to be slightly counteracted by a resistance arisingin the regenerator from diversion of currents and the friction duetoagitation of liquid and the force required to expel the collected airthrough the small openings, as F, in the re-aeration means. This smallloss, however, seems to be quite immaterial in comparison with anadvantage resulting from a transfer of heat which is explainable inaccordance with the principles of thermodynamics. As an air bubble movesupwardly it expands in volume, and is thus reduced in temperature, andat the same time is reduced in surface as compared with volume. Onreaching a regenerator, the air thus cooled by expansion is divided upinto small bubbles under practically the same pressure, but having,-fora given quantity of air,-a greatly increased proportionate surface. Thusthe aggregate area of-contact of the air with the liquid is greatlymultiplied so that heat naturally will be conducted at a correspondingrapid rate from the liquid to the air, and thereby proportionatelyincrease the volume and the consequent efliciency of such air for thereduction of thespecific gravity of the airand-liquid mixture of whichthe upflowing column, inthat part thereof, is composed.

, Owing to the conditions here briefly pointed out, and when thedescribed process is repeated at a number of.places in a high lift, theaggregate advantage thus obtained becomes a matter of very greatpractical importance. The air expansion thus obtainable byheat-transfer, introduces an economy in the use of the air in accordancewith a wellknown principle. The compressed air being sup lied to thelowermost aeration nozzle, at N, Fig. 1), and this nozzle or aerationdevice being under the maximum submergence effect, or head, of coursethis head or pressure, determines the amount of air-pres sure to besupplied.

Owing to the normally rapid escape from the liquid of the coalesced airin the lower or de-aeration zone Z the liquid is there de-aerated to theextent of such separation, and hence may be designated as de-aerated,since it will then retain only a small proportion of the air containedtherein at the time of maximum aeration. Therefore, the, termde-aerated,-as used for convenlence of description in this and in mycopending applications for improvements in air-lift apparatus anddevices,refers to and only implies a segregation or separation from theliquid of a considerable proportion of the air previously suppliedthereto. In this connection, it should be understood that in someinstances a portion of such 'contained air will or may become soabsorbed, or emulsified .as to follow along in the moving liquid columnin its passage from said lower uptake-pipe, or conduit, as P t the,

upper said pipe or conduit, as P but, this action will normally andordinarily occur only in a moderate degree, not harmful to the operationof the re-aeration means considered as a whole.

Since, as wellknown,'the function of the air bubbles is to lighten thespecific gravity of a given mass of the content of the column, it isobvious that any available gases may be used in place of atmosphericair, and hence it is to be understood that the term air is hereinemployed as a generic term for designating the air or other gases whichmay in any given instance be available for use in effecting thenecessary reduction in the weight of the fluid contained within a givenlength of the uptake pipe.

A further improvement is illustrated in Figs. 6 to 9, whereby toaccelerate the aforesaid segregativeaction arising from a slacking andbroadening of the upflowing column, within the de-aerating zone Z'. Thiszone is shown in Fig. 2 as having a relatively short height, but in Fig.6 this height, between lines 12 and 9, is much greater, and hence thevelocity-reduction of said column is also less rapid. This portion, Z",

of the regenerator'is here shown (Fig. 6) made in the form of a separateand tapering tubular member which is an extension of the main casing B.The three arts, casing B, pipe P and connecting tu e Z are readilyconnected together in practice, in a releasable manner by means of pairsof coactive flanges, and by bolts (not shown) in the simplem-annerclearly indicated'by the drawings.

Within the tubular member Z (Fig. 6), this being tapering, acolumn-rotating means is provided whereby to turn the liquid column asthis moves upwardly in the member Z The object of this rotation is toimpart to the liquid an outward momentum or centrifugal effect, tothereby increase the fluidpressure in the outer portion and thus morerapidly force the air-bubbles toward the center of the column, and todothis while the slippage is increasing by reason of the slacking of theupflow velocity of the liquid stream. 4 p

The form of said column-rotating means herein particularly illustrated,consists in a an increasing width from the lower end (Fig. 7) upwardlyto the top thereof,--Fig. 9; also,it will be desirable in someinstances, to have the spirality of an increasing pitch. In the presentinstance, two of said guides are shown, 15 and 16, but in the 'case ofconduits of small diameter, one of these may be omitted in the case ofexceptionally large conduits, three or more of said guides or blades maybe employed. Also, the width and length of these guides, as 15, 16, maybe varied to adjust their efi'ects to the requ'pements of any giveninstallation.

11 some instances, especially where the apparatus or air-lift systemoperated in a fluctuating manner, (which is sometimes unavoidable), sothat relatively large masses of air impinge against the guide or vans,

as 15, this guide may have a series of small perforations, as 17. '(Fig.6), for permitting a part of such air to pass through and thus formsmall bubbles. In such a case, these newly formed bubbles, beingof'small size and located well toward theouter side of the liquidstream, may be carried with this stream through the by-pass conduit andthus fiow upwardly into and through'the re-aeration zone, there to mixwith the bubbles comingIup from the central air chamber.

. 1 aving thus described my invention, I c a1m:

1L regenerator apparatus for air-liftscomprising, in combination, acasing for connecting a lower uptake-conduit for delivering an aeratedliquid column upwardly into the casing and an upper uptake-conduit forreceiving re-aerated liquid from the casing, said regenerator having alower deaeration zone and an upper re-aeration zone, and intermediate tothese two zones having an air-collecting chamber in position and adapted.for collecting coalesced air-bubbles from said lower zone, and providedwith means for comminuting and then delivering said. collected air intosaid upper zone, and also having a separate passage-way for acontinuously moving column of liquid from said de-aeration zone to saidre-aeration zone, whereby a column ,of liquid mixed with relativelylarge air-bubbles may be regenerated withoutcessation of upflow, into acolumn of liquid. mi-Xedwith relatively small air-bubbles'compo'sed ofair previously segrei ted from said column. I

2. fregenejratof apparatus for air-lifts comprising, in combination, acasing for connecting a 'loweri'i-ptwke-conduit for deliveringan aeratedliquid column upwardly into the casing and anupper uptake-conduit forreceiving re-aerated liquid from the casing, said regenerator having alower deaeration .zone and upper re-aeration zone, and intermed ate tothese two zones having an intermediate air-stream conduit-member inposition and adapted I f0r.c0llecting air from said lower zone, and fordelivering this air in a comminuted form intosald upper zone, and alsohaving a separate passageway for a continuously moving column of liquidfrom said de-aeration zone to said reaerationzone, whereby a column ofliquid mixed with relatively large air-bubblesmay be. regeneratedwithout cessation of upflow, into a column of liquid mixed withrelatively small air-bubbles composed of airpreviously segregated fromsaidrcolumn.

3. A regenerator apparatus for air-lifts comprising, in combination,acasing for connecting a lower uptake-conduit for delivering an aeratedliquid column upwardly intothe casing, and an upper uptake-conduit forreceiving re-aerated liquid from the easing, said regenerator having alower deaeration zone and upper re-aeration zone, and intermediate tothese two zones having inclosed therein a combined air-streamconduit-member and air-collecting chamber which is in position andadapted for collect ing air from said lower zone, and .is provided withmeans for comminuting and then delivering said collected air into saidupper zone, and also having an annular air-chamber-inclosing passage-waylfor a continuously moving column of liquid from said deaeration zone tosaid re-aeration zone.

4. In an apparatus for air-lifting liquids,

, in combination, a re-aeration means, a lower uptake-conduit connectedfor delivering liq uid upwardly into the re-aeration means,

and an upper uptake-conduit connected forreceiving re-aerated liquidfrom the re-aeration means, said re-aeratio'n' means constitutin alaterally-closed connection for said upta e-conduits and having in theupper portion thereof a re-aeration zone at the lower end of said upperconduit, and in the lower portion thereof, having an air-and-liquidseparation zone at the upper end of said,

-ducting a continuously moving column of liquid from said separationzone-and outside of the air-collecting chamber to said re-aeration zonefor delivery into the lower end of said upper uptake conduit,segregation of coalesced air-bubbles is effected from a continuouslmoving column which without cessation o upflowlng movement isre-aeratedby-newly formed small bubbles composed of the same air whichwas thus'segregated from saidcolumn.

5. In an apparatus for air-bitingl qu ds,

onduit, said re-.

whereby the air-and-liquid separation atthe upper end of said lowerconduit, and also having an air-collecting chamber verticallyintermediate to said zones and in position for collecting air from saidlower .conduit, and provided with means for comminuting and thendelivering said collected air into the liquid in the re-aeration zone atthe lower end of said upper conduit, said regenerator being alsoprovided with a channel arranged for conducting a continuously movingcolumn of liquid from said separation zone and outside of theair-collecting chamber to said re-aeration zone and then into the lowerend of said upper uptake-conduit.

6. In an apparatus for air-lifting liquids, in combination, an uptakecolumn comprising a plurality of pairs of uptake conduits arranged in aseries in which the pairs have an upwardly progressing gradation, and aseries of conduits-connecting regenerators one foreach said uptake pairand also arranged in an upwardly progressing gradation, the regeneratorof each said pair constituting a laterally-closed conduitcolmector,andhaving means in position for first collecting air and for thencomminuting and delivering the collected air into the liquid at thelower end of an upper conduit of the pair connected by such regenerator,whereby a continuously upflowing compound column of air and llquid maybe restricted as to acceleration, and may be successively regenerated atsuccessive elevations, respectively, into a column of liquid mixed withrelatively small air-bubbles composed of air previously segregated fromsaid column.

In an apparatus for air-lifting liquids, in combination, anuptake-column comprising a plurality of pairs of uptake conduits andhaving the two conduit members of one said pair arranged in an upwardlyrogressing gradation, and a series of con uits-connecting regeneratorsone for each said uptake pair, said regenerators each constituting alaterally-closed conduit connector, and having means for firstcollecting air and for then comminuting and delivering the collected airinto the liquid at the lower end of anupper conduit ofthe pair connectedby such regenerator, whereby a continuously upflowing compound column ofair and liquid may be restricted as to acceleration, and may besuccessively regenerated at sucregated from said column.

cessive elevations, respectively, into a column of liquid mixed withrelatively small air-bubbles composed of air previously seg- 8. In anapparatus for air-lifting liquids, in combination, an uptake columncomprising a plurality of pairs ofuptake conduits and having two conduitmembers of one said pair arranged in an upwardly progressing gradation,and a series of conduits-connectlng regenerators one for each saiduptake pair and also arranged in an upwardly progressing radation, saidregenerators each constituting a laterally-closed conduit connector, andhaving means for first collecting air and for then comminuting anddelivering the collected air into the liquid at the lower end of anupper conduit of the pair connected by such regenerator, whereby acontinuously upflowing compound column of air and liquid may berestricted as to acceleration, and may be successively regenerated atsuccessive elevations, respectively, into a column of liquid mixed withrelatively small air-bubbles composed of air previously segregated fromsaid column.

9. In an apparatus for air-lifting liquids, in combination, a series ofpairs of uptake conduits, and a series of conduits-connectingregenerators one for each said uptake pair, said regenerators eachconnecting a lower uptake-conduit with an upper uptake conduit, eachsaid regenerator constituting a laterally-closed conduit connector, andhaving means for collectingcoalesced air-bubbles 'from a lower conduit,and for comminuting and then delivering said collected air into theliquid at the lower end of an upper conduit, whereby a continuouslyupflowing column of liquid may be successively regenerated at successiveelevations, respectively, from a column of liquid mixed with relativelylarge air-bubbles into a column of liquidmixed with relatively smallair-bubbles composed of air previously segregated from said column.

10. In an apparatus for air-lifting liquids, in combination, a series ofuptake conduits, and a series of conduits-connecting regenerators oneforeach said uptake pair, said regenerators each connecting a loweruptakeconduit with an upper uptake conduit, each said regenerator havingmeans for comminuting air and delivering into a cont nuously upflowingcolumn of l1qu1d alrbubbles composed of air previously segregated fromsaid column.

11. 'An air-lift apparatus comprising, in combination, two uptakeconduits arranged one above the other and in alinement, and aregenerator intermediate to and connect- .ing said conduits and havingtherein an airair comminuting means, said regenerator having apassageway for de-aerated liquid to flow from said de-aeration zone tosaid reaeration zone without passing through said chamber.

12. An air-lifting apparatus comprising,

in combination, a lower uptake conduit, and a an upper uptake conduit inaxial alinement and connected bya regenerator casing in axial alinementwith said conduits and having a diameter larger than said conduits,

said casing'having at the lower end thereof an upwardly diverging zoneand having at the upper end thereof an upwardly converging zone andhaving supported therein a combined air-collecting chamber and airstreamconduit member extending from said lower zone to said upper zone, andprovided with air-comminuting means located below said upper zone.

13. An air-bubble regenerator for airlifts, comprisin a casing-bodysubstantially cylindrical in orm and longitudinally divided into twoparts and having means for releasably uniting these parts, Saidcasingbody having at each end thereof a converging zone and means for areleasable connection with an uptake conduit, in combination with acentrally-disposed air-collecting and comminuting chamber releasablysup-' ported within a mid-length zone of said casing, whereby aninclosed space surrounding said chamber "constitutes a passageway forde-aerateddiquid. I

14. An air-bubble regenerator for airlifts, comprising, in combination,a casing tubular in form and having a converging zone at one endtherefor, and an air-chamber tubular in form and shorter than thecasing, and supported within and longitudinally of the casing, andair-comminutingmeans appurtenant to said chamber and adjacent to saidconverging zone of the casing.

-15. An air-lift apparatus comprising, in

combination, two uptake conduits arranged one above the other and inalinement, and a regenerator intermediate to and connecting saidconduits and havin therein an aircollecting chamber in ahnement with theupper one of said conduits and provided with air'means, said apparatusalso comprising a de-aeration zone "below .said chamber and an upwardlycontracting zone for the re-aeration of de-aerated liquid, and saidregenerator also having a passageway for de-aerated liquid to flow fromsaid de-aeration zone to said re-aeration zone without passin throughsaid chamber.

16! n air-lifting apparatus comprising, in combination, two uptakeconduits arranged one above the other and in alinement, and aregenerator intermediate to and connecting said conduits and havingtherein an air-collecting chamber in alinement with the upper one ofsaid conduits and provided with air comminuting means, said regeneratorhaving a de-aeration zone below said chamber and an upwardly contractingzone for the re-aeration of de-aerated liquid, and also having apassageway for de-aerated liquid to flow from said de-aeration zone tosaid re-aeration zone without passing through said chamber.

17. An aim-lift apparatus comprising, in combination, a lower uptakeconduit, and an upper uptake conduit in axial alinement and connected bya regenerator casing in axial alinement with said conduits and having adiameter larger than said conduits, said casing having at the lower endthereof anupwardly diverging zone and having at the upper end thereof anupwardly converging zone, and having supported therein a combinedair-collecting chamber and air-stream conduit member extending from saidlower zone to said upper zone, and provided with air-comminuting meanslocated below said upper zone.

18. An air-lift apparatus-comprising, in

combination, a lower uptake conduit and an upper uptake conduitconnected by a regenerator casing in axial alinement with said upperconduit and having a diameter larger than said conduits, said casinghaving at the lower end thereof an upwardly diverging zone. and havingat the upper end thereof an upwardly converging zone, and having thereina combined air-collecting chamber and air-stream conduit memberintermediate to said lower and upper zones, and air-comminuting meansappurtenant to said chamber.

19. An air-bubble regenerator for airlifts, comprising, in combination,a chambered casing-body longitudinally divided into two parts and havingmeans for releasably unitlng these parts, means for releasablyconnecting the casing-body with an uptake conduit, and a centrally-disosed aircollecting and comminuting cham r releasably supported withinamid-length zone of said casing, whereby an inclosed space surroundingsaid chamber constitutes a pas: sageway for de-aerated liquid.

- 20. An air-bubble regenerator for airlifts, comprising, a casing-bodysubstantially cylindrical in form and longitudinally divided into twoparts and having means for-releasably uniting these parts, saidcasing-body having at each end thereof a con- 21. An air-bubbleregenerator for air purtenant to said chamber and adjacent to lifts,comprising, in combination, a casing said converging zone of the casing.tubular in form and having a converging zone at one end thereof, and anair-chamber EDWIN ROGERS 5 tubular in form and shorter than the casing,Witnesses:

and supported Within and longitudinally of FRANCIS H. RICHARDS,

the casing, and air-comminuting means ap- AGHILLES ROVEGNO.

